oxygenate ox·y·gen·ate (ŏk'sĭ-jə-nāt') or ox·y·gen·ize (-jə-nīz')v.ox·y·gen·at·ed or ox·y·gen·ized, ox·y·gen·at·ing or ox·y·gen·iz·ing, ox·y·gen·ates or ox·y·gen·iz·es To treat, combine, or infuse with oxygen.